RO versus tap water

[mling]

After reading all about RO, I just bought a RO/DI system. But after discussing RO with a friend, I am now having doubts about using it for my tank. In short my friend tells me that he does not like RO because it strips the water of everything and then you have to buy supplements to bring up the PH, etc.

It is true that If your county water system is “acceptable” for aquarium use, it is better to just use tap water and use water conditioners to get rid of chlorine, versus RO ?

Is there a “natural” way to raise the PH level in a reef tank ?

 

[ChrisRD]

You definitely want to stick with the water from your RO/DI over tap water.

Your friend's concerns may be valid if you're talking about drinking the water, or using it in a freshwater fish tank, but for your reef, the RO/DI is definitely the way to go.

When you top-off evaporation you want the water to be totally pure (ie. devoid of any mineral content) because that's all that's evaporating from the tank - pure water - the other stuff stays in the tank. If you kept adding that stuff in, you'd end-up with an accumulation over time.

When you're making up a batch of salt water for a water change or the initial system fill, the salt mix has all the minerals and trace elements your tank needs. So, again, it's actually better to start with pure water, devoid of anything else.

As for pH, if you have good surface agitation and water movement (ie. aeration) your tank should stay in a normal pH range. Topping off with kalkwasser will also help to keep pH up while supplementing Ca and Alk in balanced quantities (sorta kills two birds with one stone ).

HTH

 

[Anonymous]

>...Your friend's concerns may be valid if you're talking about drinking the water, or using it in a freshwater fish tank, ...

I won't use the phrase "may be valid" since it is not. There is no health concern regarding the lack of mineral even with RO/DI (even more pure than RO). It is a myth that is so wide spread that many people thinks that it is true. I won't recommand the use of RO/DI for drinking purpose for a different reason: it is a waste of money and resource. However, I use RO water for drinking and cooking.

On the other portion of "may be valid." If the RO is for top off, you still don't need to add any junk to get the pH, etc.. The reason is the same for salt water, since only thing that got evaporated is just water. For water change, however, it may be valid if you are not keeping any soft water fish. Some freshwater fish prefers soft water, and straight RO water is better in most case.

 

[ufans]

It is much easier to add supplements to the RO/DI water than to try get rid of the algae and other problems that come with tap water.

RO/DI water is not recommened for drinking only because it is expensive, it doesn't have flouride for your teeth, and the lack of minerals makes the water taste dry. If you look at a lot of the bottled water products out there like Dasani it actually adds minerals before bottling so that it "tastes like water".

It is much easier to start pure and add what you want than try to treat the effect of phosophates and silca in your aquarium. Controlling PH is something you typically have to do anyway.